Bent structure and method for manufacturing the same

Abstract

To provide a bending structure in which an end member can be attached to an axial end of a bending part by laser welding.SOLUTION: A bending structure includes a bending part 11 being elastically bendable in an axial direction, a movable part 5 as an end member to be attached to an axial end of the bending part 11, a thin-wall part 14 formed at the movable part 5 and being thinner in the axial direction than the movable part 5, a notch part 15 provided at the movable part 5 and exposing the thin-wall part 14 in the axial direction so as to apply laser beam of laser welding, and a weld zone 18 formed at the thin-wall part 14 by the laser welding and connecting the thin-wall part 14 to the bending part 11.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a bending structure used for a joint functional part such as a robot or a manipulator, and a method for manufacturing the same.

Background Art

[0002] As a conventional bending structure, as disclosed in Patent Document 1, there is known a structure in which an end member is attached to an axial end of an elastically bendable bending part.

[0003] The bending part is formed by laminating a plurality of wave washers and holding this laminated state by laser welding between the wave washers.

[0004] An end member is further laminated and attached to this bending part. At the time of this attachment, since laser light cannot be irradiated from the lamination direction between the end of the bending part and the end member, laser welding cannot be employed.

[0005] Such laser welding can obtain a strong joint in a simple process as compared with joining by solder or the like. For this reason, there are also bending parts using a coil spring, a bellows, or the like, and there has been a demand for joining an end member to such a bending part by laser welding.

Prior Art Documents

Patent Documents

[0006]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0007] The problem to be solved is that an end member could not be attached to an axial end of a bending part by laser welding. [Means for solving the problem]

[0008] The present invention comprises: a bendable portion that is elastically bendable in the axial direction; an end member attached to the axial end of the bendable portion; a thin-walled portion formed on the end member and thinner in the axial direction than the end member; an exposed portion provided on the end member that exposes the thin-walled portion so that laser light for laser welding can be irradiated on it in the axial direction; and a welded portion formed on the thin-walled portion by laser welding and connecting the thin-walled portion to the bendable portion. The thin-walled portion is made of a plate material laminated and joined to the end member, Provides a curved structure.

[0009] Furthermore, the present invention relates to a method for manufacturing a bent structure by attaching an end member to the axial end of a bent portion that is elastically bendable in the axial direction by laser welding, wherein a thin-walled portion is formed on the end member that is thinner in the axial direction than the end member, the end member is exposed so that the laser light of the laser welding can be irradiated through the exposed portion, the end member is positioned relative to the bent portion so that the thin-walled portion is on the bent portion side, and the thin-walled portion is joined to the bent portion by laser welding via the exposed portion. Furthermore, the thin-walled portion is formed by laminating and joining plate material to the end member. The present invention provides a method for manufacturing a bent structure. [Effects of the Invention]

[0010] According to the present invention, the bent structure can be realized in which an end member is attached to the axial end of the bent portion by laser welding.

[0011] According to the manufacturing method of the bent structure of the present invention, a bent structure can be manufactured by attaching an end member to the axial end of the bent portion by laser welding. [Brief explanation of the drawing]

[0012] [Figure 1] Figure 1 is a perspective view showing a bent structure according to Embodiment 1 of the present invention. [Figure 2] Figure 2 is a side view of the bent structure shown in Figure 1. [Figure 3]FIG. 3 is an enlarged view showing a main part of the bending structure of FIG. 1. [Figure 4] FIG. 4 is an enlarged view showing a main part of the bending structure of FIG. 2. [Figure 5] FIG. 5 is a plan view of the bending structure of FIG. 1. [Figure 6] FIG. 6 is a bottom view showing a welded part between a movable part of the bending structure of FIG. 1 and a flat washer. [Figure 7] FIG. 7 is a perspective view showing a movable part of a bending structure according to a modified example. [Figure 8] FIG. 8 is a perspective view showing a movable part of a bending structure according to another modified example. [Figure 9] FIG. 9 is a side view showing a manufacturing method of a bending structure according to Embodiment 1 of the present invention. [Figure 10] FIG. 10 is a side view showing a manufacturing method of a bending structure according to Embodiment 1 of the present invention. [Figure 11] FIG. 11 is a side view showing a manufacturing method of a bending structure according to Embodiment 1 of the present invention. [Figure 12] FIG. 12 is a side view showing a manufacturing method of a bending structure according to Embodiment 1 of the present invention. [Figure 13] FIG. 13 is a perspective view showing a bending structure according to Embodiment 2 of the present invention. [Figure 14] FIG. 14 is a side view of the bending structure of FIG. 13. [Figure 15] FIG. 15 is a perspective view showing a main part of a bending structure according to Embodiment 3 of the present invention.

MODE FOR CARRYING OUT THE INVENTION

[0013] <{ The object of enabling an end member to be attached to an axial end of a bent portion by laser welding is achieved by providing a thin portion that can be welded to the bent portion by irradiating the end member with laser light.

[0014] That is, the bending structure (1) includes bending portions (11, 35, 37), end members (3, 5), a thin-walled portion (14), an exposed portion (15), and a welding portion (18). The bending portions (11, 35, 37) are members that can be elastically bent with respect to the axial direction. The end members (3, 5) are attached to the axial ends of the bending portions (11, 35, 37). The thin-walled portion (14) is formed on the end members (3, 5) and is thinner in the axial direction than the end members (3, 5). The exposed portion (15) is provided on the end members (3, 5) and exposes the thin-walled portion (14) so that it can be irradiated with laser light for laser welding in the axial direction. The welding portion (18) is formed on the thin-walled portion (14) by laser welding and joins the thin-walled portion (14) to the bending portions (11, 35, 37).

[0015] The exposed portion (15) may be a notch portion that opens the thin-walled portion (14) outside the end members (3, 5).

[0016] The thin-walled portion (14) may be composed of laminated and joined plate materials on the end members (3, 5).

[0017] The bending portions (11, 35, 37) may include a plurality of wave washers (27) laminated in the axial direction and held in a laminated state by laser welding, and the thin-walled portion (14) may be a wave washer (27) laminated on the end members (3, 5) and joined by laser welding. In this case, the thin-walled portion (14) is joined by the welding portion (18) to the wave washer (27) located at the end of the plurality of wave washers (27) to form the end of the bending portions (11, 35, 37).

[0018] Also, the bending portions (11, 35, 37) may include flat washers (29) laminated in the axial direction at the ends of the plurality of wave washers (27) and held in a laminated state by laser welding. In this case, the thin-walled portion (14) is joined by laser welding to the flat washer (29) located at the end of the plurality of wave washers (27).

[0019] The manufacturing method for such a bent structure (1) involves forming a thin-walled portion (14) on the end members (3, 5) that is thinner in the axial direction than the end members (3, 5), and exposing the end members (3, 5) so that laser light for laser welding can be irradiated through the exposed portion (15). Next, the end members (3, 5) are positioned relative to the bent portions (11, 35, 37), and the thin-walled portion (14) is positioned on the side of the bent portions (11, 35, 37). Then, the thin-walled portion (14) is laser-welded to the bent portions (11, 35, 37) by laser irradiation through the exposed portion (15).

[0020] When the bent portion (11, 35, 37) is formed by multiple wave washers (27), the multiple wave washers (27) are stacked in the axial direction and the stacked state is maintained by laser welding to form the bent portion (11, 35, 37). Before or after the formation of the bent portion (11, 35, 37), a thin-walled portion (14) is formed by stacking wave washers (27) on the end members (3, 5) and joining them by laser welding. Next, the thin-walled portion (14) is joined by laser welding to the wave washers (27) located at the ends of the multiple wave washers (27) to form the end of the bent portion (11, 35, 37).

[0021] When flat washers (29) are stacked on the ends of multiple wave washers (27) at the bent portions (11, 35, 37), the thin-walled portion (14) is joined to the flat washers (29) located at the ends of the multiple wave washers (27) by laser welding. [Examples]

[0022] [Structure of the Bending Structure] Figure 1 is a perspective view showing a bent structure according to Embodiment 1 of the present invention.

[0023] Figure 2 is a side view of the bent structure shown in Figure 1.

[0024] Figure 3 is an enlarged view showing the main parts of the bent structure in Figure 1.

[0025] Figure 4 is an enlarged view showing the main parts of the bent structure in Figure 2.

[0026] Figure 5 is a plan view of the bent structure shown in Figure 1.

[0027] Figure 6 is a bottom view showing the welded joint between the movable part of the bent structure in Figure 1 and the flat washer.

[0028] The flexion structure 1 is applied to the joint function parts of various medical and industrial devices such as manipulators, robots, and actuators. The joint function part is a device, mechanism, or apparatus that has the function of a joint that flexes and extends.

[0029] The bent structure 1 of this embodiment comprises a base portion 3, a movable portion 5, and a bent portion 11.

[0030] The base 3 consists of a columnar body, such as a cylindrical body, made of metal, resin, or the like. This base 3 is attached to the end of the manipulator's shaft, etc. Note that the base 3 is not limited to a columnar body and may take an appropriate form depending on the equipment to which the bent structure 1 is applied.

[0031] The movable part 5 is supported by the base 3 by the bending part 11 so as to be displaceable in the axial direction. An end effector or the like is attached to this movable part 5, depending on the equipment to which the bending structure 1 is applied. Note that the axial direction refers to the direction along the axis of the bending structure 1, and also includes directions that are slightly inclined with respect to the axis.

[0032] The movable part 5 constitutes an end member attached to the axial end of the bent part 11, and comprises a main body part 13, a thin-walled part 14, a notched part 15 as an exposed part, and a welded part 18.

[0033] The main body 13 is formed as a columnar body from metal, resin, or the like. However, similar to the base 3, the main body 13 can take on an appropriate shape depending on the equipment to which the bendable structure 1 is applied, and is not limited to a columnar body made of metal, resin, or the like.

[0034] In this embodiment, the main body 13 has a shape in which a portion of the circumferential direction opposite to the cylindrical body is removed by the notch 15. As a result, the main body 13 has a configuration in which a fan-shaped side portion 19 is integrally provided with the cylindrical central part 17, which is opposite to the radial direction.

[0035] At the side portion 19, the movable portion 5 is connected to a flat washer 29 (hereinafter referred to as the end flat washer 29) that constitutes the end of the bent portion 11, which will be described later. In this embodiment, the connection is made by a welded portion 31 formed by laser welding. The welded portion 31 is formed at multiple locations in the circumferential direction of the end flat washer 29. Note that the connection between the end flat washer 29 and the movable portion 5 may also be made by other methods such as adhesive bonding.

[0036] Between the central part 17 and the side part 19 of the movable part 5, an arc-shaped recess 21 is provided in plan view. This recess 21 communicates in the axial direction with the insertion hole 11a of the bent part 11, which will be described later. The central part 17 is provided with a communication hole 17a that is aligned with the axial direction. The communication hole 17a communicates in the axial direction with the inner circumference of the inner member 25 of the bent part 11, which will be described later.

[0037] The thin-walled portion 14 is formed on the movable portion 5 and is thinner in the axial direction than the movable portion 5. In this embodiment, the thin-walled portion 14 consists of a part of the circumferential direction of the end flat washer 29 exposed by the notch 15. The end flat washer 29 is an annular member that overlaps the main body portion 13 of the movable portion 5 in the axial direction. Details of the end flat washer 29 (flat washer 29) will be described later.

[0038] The thin-walled portion 14 can be a simple plate material, or a plate material partially attached only to the position corresponding to the notch 15, as long as it is a plate material laminated and joined to the movable portion 5. Furthermore, the thin-walled portion 14 can also be formed by thinning a part of the movable portion 5. Additionally, the thin-walled portion 14 may be constructed using a wave washer 27 instead of a flat washer 29.

[0039] The planar shape of the thin-walled portion 14 is set according to the shape of the notch portion 15, and in this embodiment it is arc-shaped. However, the planar shape of the thin-walled portion 14 is not particularly limited as long as it can be irradiated with laser light for laser welding.

[0040] The notch 15 is provided in the movable part 5 and exposes the thin-walled portion 14 so that laser light for laser welding can be irradiated to it in the axial direction. Exposure in the axial direction means that the thin-walled portion 14 is exposed to the outside in the axial direction so that laser welding from the axial direction is possible.

[0041] Axial laser welding is a welding method performed by irradiating the axial surface of the thin-walled portion 14 with laser light, and the laser light does not need to be aligned with the axial direction. Therefore, axial exposure includes not only exposing the thin-walled portion 14 to the outside so that laser light can be irradiated along the axial direction, but also exposing the thin-walled portion 14 to the outside in a range where the laser light can be irradiated onto the surface of the thin-walled portion 14 from a direction inclined with respect to the axial direction.

[0042] In this embodiment, the notch 15 is formed along the axial direction of the main body 13, and a part of the circumferential direction of the end flat washer 29 that overlaps with the main body 13 is made a thin-walled portion 14 that is opened to the outside of the movable part 5 so that laser light can be irradiated along the axial direction.

[0043] Figure 7 shows a modified example of the notch 15. In the modified example shown in Figure 7, the notch 15 is provided from the side of the main body 13 of the movable part 5. This notch 15 opens the thin-walled part 14 to the outside in the axial direction, to the extent that the laser beam can be irradiated onto the surface of the thin-walled part 14 from a direction inclined with respect to the axial direction.

[0044] In this embodiment, a notch 15 is provided as the exposed portion, but the exposed portion is not limited to a notch 15, as long as the thin-walled portion 14 is exposed in a way that allows laser light from laser welding to be irradiated onto it. For example, the exposed portion can be a hole or made of a transparent material that can transmit laser light.

[0045] If the exposed portion is to be a hole, it is formed in the movable portion 5 along the direction of laser beam irradiation. If the welded portion 18, described later, is to be formed with only a single welding spot, the exposed portion can be made into a hole of any shape, such as a cone or cylinder, corresponding to the laser beam. If the exposed portion is to be made of a transparent material, the movable portion 5 itself can be made of a transparent material, and the portion corresponding to the thin-walled portion 14 can be used as the exposed portion.

[0046] The planar shape of the notch 15 in this embodiment is an arc shape corresponding to a part of the circumferential shape of the end flat washer 29, which is the thin-walled portion 14. However, the planar shape of the notch 15 can be arbitrarily set within the range that exposes the thin-walled portion 14 so that it can be irradiated with laser light for laser welding.

[0047] Figure 8 shows another modified example of the notch 15. The modified example in Figure 8 changes the planar shape of the notch 15 and reduces its circumferential dimensions.

[0048] The welded portion 18 is formed on the thin-walled portion 14 by laser welding, and the thin-walled portion 14 is joined to the bent portion 11. The size and shape of the welded portion 18 can be set arbitrarily, but it can be made into an appropriate shape such as a V-shape or a straight line, for example, as long as it is located in the middle of the radial and circumferential direction of the thin-walled portion 14.

[0049] The bent portion 11 is composed of an outer member 23 and an inner member 25. The inner member 25 can be omitted.

[0050] The outer member 23 comprises a plurality of wave washers 27 and a plurality of flat washers 29. The outer member 23 may also adopt other forms, such as a double coil structure, coil spring, or bellows, as described later.

[0051] Multiple wave washers 27 are stacked in the axial direction, and the stacked state is maintained by laser welding. The wave washers 27 are elastically flexible due to their elastic deformation.

[0052] Each wave washer 27 is a plate material formed in a closed or open annular shape from metal or the like. In this embodiment, the wave washer 27 is an annular plate material made of stainless steel, and the radial width and thickness between the inner and outer circumferences are constant.

[0053] This wave washer 27 is joined to an adjacent wave washer 27 by a welded portion 31 formed by laser welding at the contact portion.

[0054] In this embodiment, the wave washer 27 has a plurality of peaks 27a in the circumferential direction, and valleys 27b between adjacent peaks 27a. Between adjacent wave washers 27 in the axial direction, the peaks 27a of one wave washer 27 abut against the valleys 27b of the other wave washer. These abutting peaks 27a and valleys 27b are joined by a welded joint 31 formed by laser welding.

[0055] Furthermore, the peaks 27a and valleys 27b do not necessarily have to be in contact with each other; for example, they may be slightly offset from each other in the circumferential direction and in contact with the inclined portion 27c. In addition, the shape and material of the wave washer 27 can be appropriately changed according to the required characteristics.

[0056] Multiple flat washers 29 are stacked axially on both ends of multiple wave washers 27, and the stacked state is maintained by laser welding. In this embodiment, three flat washers 29 are stacked.

[0057] Each flat washer 29 is a plate material formed in a closed or open annular shape from metal or the like, and is made of the same material as the wave washer 27, has the same inner and outer diameters and thickness, and is flat. Therefore, when the outer member 23 is bent, the flat washers 29 deform together with the wave washers 27 so that they open up from each other, but the amount of deformation is smaller than that of the wave washers 27. Note that the flat washers 29 may be made from a different material than the wave washers 27.

[0058] The flat washer 29 and the wave washer 27 are joined by a laser-welded joint 31 at the contact points between the flat washer 29 and the wave washer 27.

[0059] The connections between the flat washers 29 and between the flat washers 29 and the base 3 and movable part 5 are made by welds 31 at positions that are sequentially displaced in the circumferential direction, following the same principle as the connections between the wave washers 27.

[0060] The flat washer 29 may be provided on only one end and one end of the multiple wave washers 27. Furthermore, the flat washer 29 can be omitted entirely.

[0061] The outer member 23 in this configuration has an insertion hole 11a that penetrates axially. A drive wire (not shown) is inserted through the insertion hole 11a, and the outer member 23 of the bent portion 11 also functions as a guide for the drive wire.

[0062] One end of the drive wire is connected to the movable part 5, and the other end of the drive wire is located on the base part 3 side, allowing it to be pulled. This pulling causes the bending part 11 to bend.

[0063] The inner member 25 is composed of a coil spring, such as a tightly packed spring or a double-coil spring, made of metal, resin, or the like. The inner member 25 can take various forms and may be composed of a flexible cylindrical body or the like.

[0064] The inner member 25 is configured to bend and extend in the axial direction as a whole, and to suppress compression in the axial direction. Furthermore, in the case of a double coil structure, the length of the axial center of the inner member 25 is substantially constant before, during, and after bending. Therefore, the path length of the member inserted inside the inner member 25 can be kept constant.

[0065] [Manufacturing method for a bent structure] Figures 9 to 12 are perspective views showing the manufacturing method of the bent structure 1.

[0066] The manufacturing method for the bent structure 1 in this embodiment involves attaching the movable part 5 to the axial end of the bent part 11 by laser welding, as shown in Figures 9 to 12. Laser welding can be performed using any appropriate method, such as a carbon dioxide laser, YAG (Yttrium Aluminum Garnet) laser, or fiber laser.

[0067] In this manufacturing method, after forming the bent portion 11 and the thin-walled portion 14 on the movable portion 5, the thin-walled portion 14 of the movable portion 5 is joined to the bent portion 11 by laser welding. Note that the order in which the bent portion 11 is formed and the thin-walled portion 14 on the movable portion 5 are formed may be reversed.

[0068] In forming the bent portion 11, as shown in Figure 9, first, multiple flat washers 29 of the outer member 23 are stacked axially on the base portion 3, and the stacked state is maintained by laser welding from the axial direction.

[0069] Laser welding is performed by irradiating the contact portion of the flat washer 29 with the base 3 and the contact portion between the flat washers 29 each time a flat washer 29 is stacked in the axial direction with a laser beam. This forms a welded portion 31, joining the contact portion between the base 3 and the flat washer 29 and the contact portion between the flat washers 29.

[0070] The base 3 and the flat washer 29, and the flat washers 29 themselves, are in contact over their entire circumferential surface, but the laser beam irradiation area is only a portion of that contact area in the circumferential direction. These laser beam irradiation areas are displaced circumferentially, following the direction of the contact areas between the wave washers 27.

[0071] Next, as shown in Figure 10, multiple wave washers 27 are stacked axially on multiple stacked flat washers 29, and the stacked state is maintained by laser welding from the axial direction.

[0072] Laser welding is performed by irradiating the contact areas between the flat washer 29 and the wave washer 27, and between the wave washers 27 themselves, each time a wave washer 27 is stacked in the axial direction. This forms a welded joint 31, joining the flat washer 29 and the wave washer 27, and the wave washers 27 themselves.

[0073] The contact portion between the flat washer 29 and the wave washer 27 is the portion where the valley portion 27 of the wave washer 27 contacts the flat washer 29, and the contact portion between two wave washers 27 is the portion where the peak portion 27a and the valley portion 27b of adjacent wave washers 27 contact each other.

[0074] Next, as shown in Figure 11, flat washers 29 are stacked axially on a plurality of stacked wave washers 27, and the stacked state is maintained by laser welding from the axial direction. The stacked flat washers 29 consist of two washers, excluding the end flat washers 29 that constitute the thin-walled portion 14.

[0075] In this way, the wave washers 27 and flat washers 29, excluding the end flat washers 29, are stacked and the stacked state is maintained to form the outer member 23 of the bent portion 11. After the formation of this outer member 23, the inner member 25 is placed inside the outer member 23.

[0076] Alternatively, the inner member 25 may be placed before the outer member 23 is formed, and the flat washer 29 and wave washer 27 may be stacked by inserting the inner member 25.

[0077] In forming the thin-walled portion 14 on the movable portion 5, as shown in Figure 12, the thin-walled portion 14 is formed on the movable portion 5, which is thinner in the axial direction than the movable portion 5, and is exposed to the laser beam of laser welding through a notch 15 provided on the movable portion 5.

[0078] In this embodiment, end flat washers 29 are stacked axially on the movable part 5 and joined by laser welding to form a thin-walled portion 14.

[0079] The stacking of end flat washers 29 is performed by overlapping the end flat washers 29 with respect to the bottom surface of the movable part 5. Laser welding is performed by irradiating the contact portion of the end flat washer 29 with the movable part 5 with laser light from the axial direction. This forms a welded portion 31, connecting the end flat washer 29 to the movable part 5.

[0080] The end flat washer 29, which is connected to the movable part 5, has a portion of its circumferential direction facing the notch 15, and its surface is exposed to the outside through the notch 15. This forms a thin-walled portion 14.

[0081] With the thin-walled portion 14 formed on the bent portion 11 and the movable portion 5, the movable portion 5 is attached to the bent portion 11.

[0082] When attaching the movable part 5 to the bent part 11, the thin-walled part 14 is joined to the bent part 11 by laser welding through the notch 15, as shown in Figure 4.

[0083] For installation, the movable part 5 is first positioned relative to the bent part 11. This positioning ensures that the end wave washer 27 is positioned between the bent part 11 and the movable part 5, with the bent part 11 facing the end wave washer 27, and that the thin-walled part 14 aligns circumferentially with the peaks 27 of the wave washer 27 to which it is joined.

[0084] As a result, the thin-walled portion 14 comes into contact with the peak portion 27 of the wave washer 27 to which it is joined. Laser welding is performed by irradiating the portion of the thin-walled portion 14 that comes into contact with the wave washer 27 through the notch portion 15. This forms a welded portion 18 on the thin-walled portion 14, joining the thin-walled portion 14 to the wave washer 27 located at its end.

[0085] Through this connection, the movable part 5 is joined to the bent part 11, and the end wave washer 27 that was joined to the movable part 5 forms the end of the bent part 11 (outer member 23).

[0086] Thus, the process from forming the bent portion 11 to connecting the movable portion 5 to the bent portion 11 can be easily carried out by stacking flat washers 29, wave washers 27, and the movable portion 5 from the axial direction and then laser welding.

[0087] [Effects of Example 1] As described above, the bendable structure 1 of this embodiment comprises a bendable portion 11 that can be elastically bent in the axial direction, a movable portion 5 attached to the axial end of the bendable portion 11, a thin-walled portion 14 formed on the movable portion 5 and thinner in the axial direction than the movable portion 5, a notch 15 provided on the movable portion 5 that exposes the thin-walled portion 14 so that laser light for laser welding can be irradiated on it in the axial direction, and a welded portion 18 formed on the thin-walled portion 14 by laser welding and connecting the thin-walled portion 14 to the bendable portion 11.

[0088] Therefore, the bent structure 1 of this embodiment can be made to have a structure in which a movable part 5 is attached to the axial end of the bent part 11 by laser welding.

[0089] In the manufacturing method of the bent structure 1, a thin-walled portion 14 is formed on the movable portion 5, which is thinner in the axial direction than the movable portion 5. A notch 15 is provided on the movable portion 5 to expose it so that laser light for laser welding can be irradiated onto it. The movable portion 5 is positioned relative to the bent portion 11, the thin-walled portion 14 is positioned on the bent portion 11 side, and the thin-walled portion 14 is joined to the bent portion 11 by laser welding through the notch 15.

[0090] Therefore, the movable part 5 can be attached to the axial end of the bent part 11 by laser welding, making it possible to easily and reliably manufacture the bent structure 1.

[0091] Furthermore, the notch 15 allows the thin-walled portion 14 to be exposed to the outside of the movable portion 5, making it easy to irradiate the thin-walled portion 14 with laser light.

[0092] Furthermore, the thin-walled portion 14 is made of a flat washer 29, which is a plate material laminated and joined to the movable portion 5, and can therefore be easily formed.

[0093] In particular, the bent portion 11 is formed by stacking multiple wave washers 27 and flat washers 29 at their ends in the axial direction, and the stacked state is maintained by laser welding, while the thin-walled portion 14 is formed using the flat washers 29 that constitute the ends of the bent portion 11.

[0094] Therefore, the thin-walled portion 14 can be easily formed without using special components. Moreover, the process from forming the bent portion 11 to attaching the movable portion 5 to the bent portion 11 can be easily carried out by lamination of flat washers 29 and wave washers 27 from the axial direction, and laser welding of the movable portion 5. [Examples]

[0095] Figure 13 is a perspective view showing a bent structure according to Embodiment 2 of the present invention. Figure 14 is a side view of the bent structure of Figure 13. In Embodiment 2, the same reference numerals are used for components corresponding to Embodiment 1, and redundant explanations are omitted.

[0096] The bending structure 1 in this embodiment has a multi-joint structure. That is, the bending structure 1 has a multi-joint section 33 between the base section 3 and the movable section 5.

[0097] The multi-joint section 33 is constructed by attaching the first bending section 35 and the second bending section 37 to both sides in the axial direction of the cylindrical intermediate section 39.

[0098] The first bent portion 35 and the second bent portion 37 have the same configuration as the bent portion 11 of Embodiment 1, except for their axial length. A movable portion 5 and a base portion 3 are attached to the ends of the first bent portion 35 and the second bent portion 37, respectively. The base portion 3 in this embodiment has the same configuration as the movable portion 5 and constitutes an end member in the same way as the movable portion 5.

[0099] During the manufacturing of the bent structure 1, multiple flat washers 29 and multiple wave washers 27 are stacked on both sides of the intermediate portion 39 in the axial direction to form the outer members 23 of the first bent portion 35 and the second bent portion 37, and the movable portion 5 and the base portion 3 are attached to the ends of these outer members 23 by laser welding, respectively.

[0100] The lamination of the flat washer 29 and the multiple wave washers 27, as well as the attachment of the movable part 5 and the base part 3 by laser welding, are the same as in Example 1.

[0101] The base portion 3 may be configured in the same manner as in Example 1, and the intermediate portion 39 may be configured in the same manner as the movable portion 5 in Example 1.

[0102] In this second example, the same effects and advantages as in the first example can be achieved. [Examples]

[0103] Figure 15 is a perspective view showing the main parts of a bent structure according to Embodiment 3 of the present invention. In Embodiment 3, the same reference numerals are used for components corresponding to Embodiment 1, and redundant explanations are omitted.

[0104] In this embodiment, the bent structure 1 omits the flat washer 29 from the outer member 23. Accordingly, the thin-walled portion 14 consists of a wave washer 27 connected to the movable portion 5. The rest is the same as in Embodiment 1. Note that the thin-walled portion 14 may also consist of a flat washer connected to the movable portion 5, as in Embodiment 1. Furthermore, the flat washer 29 on the base portion 3 side can also be omitted.

[0105] In this third example, the same effects and advantages as in the first example can be achieved. [Explanation of Symbols]

[0106] 1 Bent structure 3. Base (end member) 5. Movable parts (end members) 11. Flexed section 14 Thin-walled section 15. Notch (exposed part) 27 Wave Washer 29 Flat Washer 35 1st bending part 37 Second bending part

Claims

1. A flexible portion that can be elastically bent in the axial direction, An end member attached to the axial end of the bent portion, A thin-walled portion is formed on the end member and is thinner in the axial direction than the end member, An exposed portion provided on the end member is provided to expose the thin-walled portion so that laser light for laser welding can be irradiated in the axial direction, A welded portion formed in the thin-walled portion by the laser welding and connecting the thin-walled portion to the bent portion, Equipped with, The thin-walled portion is made of plate material laminated and joined to the end member. bending structure.

2. A bending structure according to claim 1, The exposed portion is a notch that opens the thin-walled portion to the outside of the end member. bending structure.

3. A bent structure according to claim 1 or 2, The bent portion comprises a plurality of wave washers stacked in the axial direction and whose stacked state is maintained by the laser welding. The thin-walled portion consists of wave washers laminated on the end member and joined by laser welding, and the end of the bent portion is formed by the wave washers that are joined by the welded portion to the wave washers located at the ends of the plurality of wave washers to form the thin-walled portion. bending structure.

4. A bent structure according to claim 1 or 2, The bent portion comprises a plurality of wave washers stacked in the axial direction and maintained in a stacked state by laser welding, and flat washers stacked in the axial direction at the ends of the plurality of wave washers and maintained in a stacked state by laser welding. The thin-walled portion is joined to the flat washer located at the end of the plurality of wave washers by laser welding. bending structure.

5. A method for manufacturing a bent structure, comprising attaching an end member to the axial end of a bent portion that is elastically bendable in the axial direction by laser welding, A thin-walled portion is formed on the end member that is thinner in the axial direction than the end member, and the end member is exposed so that the laser light of the laser welding can be irradiated through the exposed portion provided on the end member. Position the end member relative to the bent portion so that the thin-walled portion is located on the bent portion side. The thin-walled portion is joined to the bent portion by laser welding through the exposed portion. The thin-walled portion is formed by laminating and joining plate material to the end member. A method for manufacturing a bent structure.

6. A method for manufacturing a bent structure according to claim 5, The exposed portion is a notch or hole that opens the thin-walled portion to the outside of the end member. A method for manufacturing a bent structure.

7. A method for manufacturing a bent structure according to claim 5 or 6, The bent portion is formed by stacking multiple wave washers in the axial direction and maintaining the stacked state by laser welding. The thin-walled portion is formed by stacking wave washers on the end member and joining them by laser welding. The thin-walled portion is joined to wave washers located at the ends of the plurality of wave washers by laser welding, and the end of the bent portion is formed by the wave washers that form the thin-walled portion. A method for manufacturing a bent structure.

8. A method for manufacturing a bent structure according to claim 5 or 6, Multiple wave washers are stacked in the axial direction and the stacked state is maintained by laser welding, and flat washers are stacked on the ends of the multiple wave washers in the axial direction and the stacked state is maintained by laser welding to form the bent portion. The thin-walled portion is joined to the flat washer located at the end of the plurality of wave washers by laser welding. A method for manufacturing a bent structure.

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